Conventionally, electrical apparatus such as transformers, reactors, and magnetrons have employed insulated electric wires made of aluminum as their core wires, in order to reduce weight of the electrical apparatus. Hereinafter, an insulated electric wire in which its core wire is made of aluminum and the outer peripheral surface of the core wire is coated with an insulating coating, is referred to as an aluminum electric wire. Aluminum has characteristics that it tends to suffer a deformation due to a creep phenomenon. Hereinafter, the deformation due to the creep phenomenon is referred to as the creep deformation. In the aluminum electric wire, its stress is relaxed when the creep deformation progresses. Hereinafter, such the relaxation of the stress caused by the creep deformation is referred to as the stress relaxation.
Concerning connections of aluminum electric wires, there have been proposals to address the creep deformation of aluminum, as shown in Patent Literatures 1 and 2.
In Patent Literature 1, a configuration is proposed in which a crimp terminal has a groove formed in a crimping part thereof, with the crimp terminal being connected to the aluminum electric wire. In Patent Literature 1, the formation of the groove is expected to address the creep deformation. Note that the crimp terminal referred in Patent Literature 1 corresponds to the connection terminal according to the present application.
In Patent Literature 2, the proposed connection terminal is such that a plurality of strain regions is formed in a plate-like part included in the connection terminal. The plate-like part is formed by folding a crimping part included in the connection terminal. In Patent Literature 2, the formation of the plurality of the strain regions is expected to address the creep deformation.